Bryophyta

moss-on-tree.jpg

By: Davis Abarca, Kim Brown ,and Lili Peet

Period 4


What is Phylum Bryophyta?

Bryophytes have many characteristics. Seeing as they are mosses, they are different from many other plants. One characteristic of bryophytes is that they have no true vascular tissue. They do contain special tissue that is used for the transportation of water, but they contain no real vascular tissue. Bryophytes are also known for their gametophyte phase, because it is the dominant phase in mosses. Gametophyte is the haploid multicellular phase that plants that plants undergo while each of their cells contains one set of chromosomes. It is the most commonly known phase in mosses. Byrophyta doesn't reproduce through seeds or pollen like most other plants, they produce through spores. They are seedless plants and don't have flowers that would hold pollen so they reproduce through spores. They're also unisexual or bisexual, meaning that they can be both genders or both.

What is the life cycle of Byrophytes?

A bryophyte is a haploid which means it only has one set of chromosomes as opposed to a diploid cell which has two, like humans having an egg and sperm. The male and female sex organs of bryophyta are called antheridia and archegonia. When a halpoid sperm cell is released from the antheridia and reaches the egg cell, archegonia the egg becomes fertilized to produce a diploid cell. The fertilized egg is now a haploid sporophyte cell. The "foot" of the sporophyte is what will develop into the spore capsule. The seta is a short "stem" like structure that connects the foot to the gametophyte which is equivalent to eh base of a plant, it's roots. By the time that the sporophyte matures the spore capsule will contain halpoid spores.

What plants and classes are in the Phylum Bryophyta?

A class under the phyla of Bryophytes is Takakiopsida. They are an unusual type of moss that look like a typical layer of moss on a rock, but they are green little shots that grow on a turf. These green little shoots that grow from the turf extend about 1cm tall. They also have short leaves which stretch about 1mm long. Another class under the moss phyla is Sphagnopsida. They are a type of moss that is also called peat moss because of its widespread mires and peat bogs. Andreaeopsida, another class, is a family of moss that looks reddish and blackish sometimes and has the appearance of a shoot. Their stems are irregularly branched and their leaves differ in various shapes and sizes depending on the genus.
Some of the plants in the bryophyta phylum are mosses, liverworts, and hornworts. Some specific types of mosses are Dicranoweisia cirrata; a moss most commonly found in Britain, Fisidens Adianthoides; lives in moist mountainous terrain, and Sphagnum; enjoys occupying bogs. (Bogs are wet muddy lands to soft to support a full body weight.) Some examples of liverworts are, Marchantia polymorpha; this plant is usually found in moist flowerpot soils in greenhouses or outdoors, Riccardia pinguis; a plant that loves, loves, loves the wet, it will most likely be found in swampy marsh-like areas.

Does Byrophyta have a vascular system?

In a plant the vascular system is a tube like tissue climbing through the stem. The few plants that don't have this vascular tissue are subject to only ever reaching a few inches in height. This occurs in non-vascular plants, pretty self explanatory. The only terrestrial non-vascular plants included mosses, hornworts, and liverworts. Considering there are only 3 terrestrial non-vascular plants you can tell that being non-vascular is not a common trait among the plant species alive today. The main characteristics of a plant's vascular system are xylem and phloem. Xylem is closest to the center of the root his primary purpose is to distribute water throughout the plant. Phloem on the other hand is closer to the outlying area of the vascular system, and it's primary purpose is to distribute nutrients throughout the plant. Byrophytes, mosses, don't have a vascular system. Moss only grow in moist areas because of this because they can't survive in a hot dry area. They can't grow tall because of this, but they can grow to about a yard long per "patch".

The Plant's Parts and what they do

Plants leaves are the powerhouse of the plant, and in most cases they are where food are produced. Leaves collect sunlight and use the process of photosynthesis to make food and energy for the plant. Chlorophyll is the molecule in the leaves that takes sunlight and turns it into energy for the plant. Plant roots job is to absorb water and nutrients out of the soil, keep the plant stationary, be a storage center of the plants food, and to prevent soil erosion. Plant stems are like the "high way" of the plant. They carry the nutrients and water from the leaves to the roots and vice versa. They also give support to the plant so that it can reach the sunlight to get nutrients and energy.
Bryophytes don't have roots, stems with xylem and phloem, and leaves like more developed plants. They don't have roots like other plants because they mainly grow on other plants like trees or the forest floor itself which is why it's commonly referred to as the forests living carpet. They do have simple roots called rhizomes which are horizontal roots that don't go very deep into the ground. Even though they don't have leaves like most plants do, moss still uses photosynthesis to get food. The area they live in must be equally moist, but still get enough sunlight.

Why are Bryophytes Evolutionarily successful?

Bryophyta is evolutionarily successful because of everything that it's able to do and all it's uses. For example some animals eat moss, while humans use a specific moss, peat moss, as a fuel source, and moss is also a great way in preventing erosion. It does have it's flaws though. Moss can't survive in areas that aren't moist because of their lack of a vascular system which would lead to them going extinct or "thinning out" if there suddenly became a lack of moist areas.

Now that you've learned about Bryophytes, Mosses you can test yourself with this test

http://www.mcwdn.org/Plants/MossesQuiz.html

Sources Sited

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"Biodiversity Plants." Canterbury Environmental Education Centre, Kent, UK. Web. 26 May 2011. <http://www.naturegrid.org.uk/biodiversity/plants/crypmoss.html>
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Stotler, Dr. Raymond E., and Dr. Barbara J. Crandall-Stotler. "What Are Bryophytes." Bryophytes. Department of Plant Biology, 2005. Web. 26 May 2011
<http://bryophytes.plant.siu.edu/bryojustified.html>.
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http://www.enchantedlearning.com/subjects/plants/leaf/